Light aircraft used in winter environments having snow, slush and ice covered air fields, landing and takeoff areas and lakes have landing gear equipped with snow skis. The skis have elongated bodies with generally flat bottom surfaces that slide along snow and ice surfaces. Airplane taxi roads, parking and fueling areas and hangers are normally cleared of snow and ice exposing the bare ground, roadway surface and hanger floor. Airplanes equipped with snow skis are not normally taxied on hard surfaces as the airplanes can nose over due to the resistance to movement of the skis along these hard surfaces. Also, the skis can be damaged as they slide along the hard surfaces. Combination snow skis and wheels have been designed to allow use of the skis on snow and ice surfaces and wheels on hard surfaces. The wheels remain attached to the skis during takeoff, flight and landing of the airplane. Examples of combined airplane landing gear having combined snow skis and wheels are illustrated in the following U.S. patents.
R. Sulnier in U.S. Pat. No. 2,106,934 discloses an airplane landing gear having combined skis and wheels. A plurality of linkages connect the skis to horizontal beams mounted on the axles for the wheels. Hydraulic cylinders are operated to raise and lower the skis relative to the wheels to allow the airplane to be either supported on a surface with the skis or wheels. The wheels are permanent parts of the landing gear.
F. J. Ditter in U.S. Pat. No. 2,733,026 discloses an aircraft ski connected to a wheel movable to a down position to retain the ski in an elevated position above a support surface whereby the wheel supports the aircraft on the surface. A piston and cylinder assembly connected to a crank arm functions to selectively raise and lower the wheel relative to the ski.
W. K. Landes in U.S. Pat. No. 3,128,065 discloses an aircraft ski having a generally flat runner portion and a raised pedestal portion surrounding a landing wheel receiving well accommodating a landing wheel. An axle assembly for the wheel is journaled on ski trunnions secured to the pedestal portion of the ski. A shock cord and safety cable attached to the toe and heel of the ski controls the attitude of the ski. The ski is a flotation device that prevents the wheel from bogging down in snow, swampy areas and muskeg. The wheel is a permanent part of the landing gear.
R. J. Schneider in U.S. Pat. No. 5,390,151 discloses an aircraft ski associated with a steerable castering tail wheel. The ski has a pedestal straddling the wheel. A wheel axle pivotally attaches the ski pedestal to the landing gear. The wheel is a permanent part of the landing gear.